A conventional emergency lighting device is generally designed to have a backup power supply, e.g., battery, inside the device, and is used to illuminate a light during a period of power outage.
In a normal circumstance, the emergency lighting device is on a standby mode as connecting to an alternating current (AC) power source, e.g., an electrical wall outlet, for maintaining the inside battery to be fully charged. The emergency lighting device is switched to be powered by a direct current (DC) power source, i.e., the battery, for illuminating the light once a power outage state is detected.
The emergency lighting device is an important facility in a place since it takes a responsibility for illuminating emergency light in an emergency situation. For example, when a place fires, the emergency lighting device is almost the only device that still works during power outage. The emergency lighting device can assist the fire fighters to enter the fire scene and to evacuate the trapped persons.
The prior documents such as “Indoor Global Positioning System with Centimeter Accuracy Using Wi-Fi IEEE Signal Processing Magazine November 2016, Yi Han, Yan Chen, and K. J. Ray Liu 1053-5888/16©20161EEE” and “CSI-based Indoor Localization Kaishun Wu Member, IEEE Jiang Xiao, Student Member, IEEE, Youwen Yi Student Member, IEEE, Dihu Chen, Xiaonan Luo and Lionel M. Ni Fellow, IEEE” that disclosed that CSI (Channel State Information) generated by transmitter and receiver of the wireless device can be used to conduct life detection, for example CSI breathing detection and CSI motion detection, by analyzing the signals generated by the mobile device held by a person. The approaches of human detection can be used in the emergency procedure.